Smyslov Variation

The Smyslov Variation, named after the seventh World Champion Vasily Smyslov, arises when White answers 4...d6 with 5. Bg5 instead of the usual 5. e4. The bishop pins the f6-knight and develops before White decides how to treat the center. The e-pawn remains on e2, so White keeps the choice between a later e4 and a more restrained e3 setup. Compared with the Averbakh Variation, the bishop reaches g5 earlier and with the knight already on f3. One consequence of the delayed e4 is that the c8-h3 diagonal stays open for Black's light-squared bishop, and engines rank 5...Bf5 among Black's best replies.

In practice Black usually castles, and 5...O-O accounts for about three quarters of games. The main alternatives are 5...Nbd7, which prepares ...e5, and 5...h6, which asks the bishop at once whether it will retreat or capture on f6. The variation is an occasional choice rather than a main battleground of the King's Indian. Engines consider the position after 5. Bg5 roughly balanced, and online results are almost evenly split, with very few draws.